Solve light stress by tuning down light schedule?

[Scirzo]

I'm currently running GSC auto by fastbuds. It's my first micro grow. I prepared well before I started and even though I have to say that these plants seem to me to be very forgiving, I have had no trouble whatsoever in getting them to their 6th flowering week. They do grow a lot slower then fastbuds says on the package, but I expected as much, since I am working with a 144W LED on 60x60cm and about 60cm height from the rim of the pots to the lamp. Anyways...there's some nice buds. I reckon they've two to three weeks to go still. Only now the three highest buds show symptoms of light stress. I don't have any more space to hang my lamp higher. So the only remaining solutions I found were bend or even snap (supercrop) the branches. So I went ahead and bent them in a 60° angle and moved the pots so the buds were all the way to the side in stead of right in the center.
They've survived the procedure, so it seems, by the way.
But then I took some puffs of very nice Amnesia Haze and she told me: light stress...the solutions that are available all focus on getting the buds away from the light...what weird stressful methods! Why not just change the light schedule? These are autoflowers...the don't care about the light schedule. Sure enough: "more light = more yield", but in this particular case it might not. It might be better to switch my schedule from 20/4 to 16/8. By doing so the buds get less light and a longer period of rest (also known to be a remedy after a stressful period)
Then slight Amnesia "paranoia" kicked in...: could it be this simple? And if so, why can't I find this solution anywhere on the Internet yet...? I must be wrong...It probably doesn't work like that...
So, my question: has anyone of you ever tried this as a solution to light stress?

 

[Chester]

I often reduce the hours of light towards the end of the grow and sometimes sooner ...

 

[Scirzo]

Thanks for responding! Why do you do this? To prevent light stress, or is it a means of simulating the suns receding light hours. And if so what are the effects of doing so? I'm very interested.

 

[Chester]

Although too much light can be stressful to some plants other plants prefer as much as they can get ... reducing the number of light hours also reduces temps for the time the light is off ... photo-sensitive plants grow buds at 12/12 ... Once my plants have become sufficiently bulked up I reduce the hours their last week or more to allow the plants to be finished but not beat down ...

 

[Scirzo]

 

[Waira]

... get us pics please, so we can assess,. and confirm,... at that distance, you should be OK,.....
That said, reducing hours can help, if they're right on the edge; yield loss form 20/4 to 16/8 won't be too bad as long as you have your nutes dialed in... If they're getting significant damage, then reducing hours isn't going to help much,... this is an intensity issue; long roast, short roast, it's still roasting, right? It can reduce potency and terpene content as well,.. So, pics will tell the tale here!

 

[Scirzo]

Thanks! Roasting is roasting, yes. But does it work the same with plants as with humans, for instance? Some people get sunburn if exposed to long. If they take it easy with the time spent in the sun, they won't burn. Now, as I've said, I know it will result in lower yields, because light = food = yield for plants. But since autos will always follow their programmed lifecycle no matter what light regime, it seems to me that reducing light hours could prevent light stress. And I think you say the same. You're mainly just worried about the yield, which is understandable.

I've already taken measures to solve my problem. Maybe it is indeed the best solution after all: I decided to supercrop both colas and put them at an angle away from the light and away from the cente. I replaced the pots so that those colas are now all the way on the outside of the light. One even is in the "no reflexion zone" from my carbon filter. Both are, by the way, recovering as if nothing has ever happened to them, thank you very much. I decided to move the pots around every now and then these last few days to get the other buds as much light as possible and at the same time keeping the full exposure at a minimum for the two larger ones. The ladies don't care. Maybe even better, they seem to like it. The pics included was the 15th of April. It was the end of week 9 since they sprouted. I just (mildly) supercropped the one pictured from the side.
I figure at least two, maybe even three weeks to go before harvest. Only now the first brown hairs are starting to show and all the trichomes are glass. It's GSC by Fastbuds. It will take me a fair bit longer than they promised, by the way. 8-9 weeks the package read.
I don't mind. I am going for taste! And I am patient. Already just the 6.5pH water since these pictures.
That also might have helped restrain the stress symptoms. Because, all the way until then, I took Fastbuds' advice of giving them plenty of nutrients. I water manually and gave nutes every time since they were 17 days old and gradually upped the dose. If you look closely at the leave tips, you can see the slight burning. This isn't just on the leaves with the light stress symptoms, but also on the lower leaves. Which tells me this is a nutrient burn. I am a noob. But I concluded, from everything you guys over here and on several great other websites, have taught me, that I might have two problems. I spotted both early and responded quickly. Also something I learned from all of you.
Maybe I am totally wrong and this yellowing of (only!) the top leaves of the colas sticking out at about 4" of my 144W LED, where 16" is advised, is normal at this stage. But as far as I have learned is that yellowing of the leaves is sort of normal on the lower branches in the shades....If it was only the nutrients: problem solved. If it was only the light: problem solved. I was quite confident in the supercropping solution after some studying on the web, so I went ahead and did it. I like having a result I can be proud of with this first grow. I think I will be. I'd rather take some timely measures and have slightly less yield but good quality than loads and loads of bogus taste.
So, after all this Wake and Bake talk by me, can I ask you some extra questions?
1. Is it light stress (see pics)?
2. Do light stress and too many nutrients reinforce each other? I seem to be connecting info I read into that question.
3. Can you also spot the nutrient burn on the tips?
4. Can you estimate if I am right in thinking these have got at least two weeks, maybe even three to go?

Thanks so much!

 

[Rev. Green Genes]

No it is not the same in humans as plants. If this was UV light you're talking about, reduced duration would help. But you are not taking away something damaging, you are taking away something beneficial.

My Amnesia got light burn when my tent proved too short, and I ended up converting to a grow closet. It made her turn into a hermie too. Supercropping was a good choice, the Amnesia didn't burn until it had been touching the light itself. Like Waira said, the intensity of light and heat are the issues. Increased air flow over the canopy will help as long it's within it's heat threshold.

 

[Scirzo]

Thanks a lot for clarifying. Your help is much appreciated!

 

[Rev. Green Genes]

The Bowen ratio works for this. The two types of evaporation are 'evapo-transpiration' and 'sensible' Sensible is caused by a fan blowing over a rough surface outline (wind), creating eddies of air, and unpredictable currents through the canopy. It reduces temperature with less loss of water, and allows for more carbon uptake becuase the stomata can stay open. Transpiration is the plant pulling water up from the roots by capillary action, and releasing it through the leaves.

Basically, cool it with increased air flow and you will lose less water, and reduce temperatures at the point of air movement.

sorry if all this sciency talk bothers you, I get into this stuff. Can't help myself. You gave me an opportunity to brush up on ecology principles.